Question 345374
Substitute {{{x=2(y+z)}}} into eq. 1 and eq. 2,
1.{{{x+y+z=1800}}}
1.{{{2y+2z+y+z=1800}}}
1.{{{3y+3z=1800}}}
1.{{{y+z=600}}}
.
.
.

2.{{{20x+35y+50z=48000}}}
2.{{{40y+40z+35y+50z=48000}}}
2.{{{75y+90z=48000}}}
2.{{{5y+6z=3200}}}
From eq. 1,
{{{y=600-z}}}
Substitute into eq. 2,
{{{5(600-z)+6z=3200}}}
{{{3000-5z+6z=3200}}}
{{{highlight(z=200)}}}
Then,
{{{y=600-200}}}
{{{highlight(y=400)}}}
And finally,
{{{x=2(y+z)}}}
{{{x=2(400+200)}}}
{{{highlight(x=1200)}}}